Look at the related word, sam-yam: to guide horses, senses, passions, to press close to. There is the image of the rider, pressing close to the horse, running across the land, the horse and rider joined in the ecstasy of movement.

saṃyam

(H1)

saṃ- √ yam [L=225626]

P.

-yacchati √ (rarely A1.) , to hold together , hold in , hold fast , restrain , curb , suppress , control , govern , guide (horses , the senses , passions) RV. &c ; to tie up , bind together (hair or a garment) MBh. Ka1v. &c ; to put together , heap up (A1. " for one's self ") Pa1n2. 1-3 , 75 Sch. ; to shut up , close (a door) Bhag. ; to press close to or against Sus3r. ; to present with , give to (A1. with instr. of person , when the action is permitted P. with dat. , when the action is not permitted) Pa1n2. 1-3 , 35 : Caus.-yamayati (cf.-yamita) , to cause to restrain &c ; to bind up (the hair) Ven2is.